Papers by Author: Jing Zhong

Abstract: DMF wastewater from the PU synthetic leather industries was filtrated by ZrO2 micro-filtration membranes with an average pore size of 0.2μm. The membrane fouling mechanism was analyzed by resistance-in series model. The results indicated that the resistance from the particles sedimentation on membrane surface accounting for 76% of the total resistances. The technology of backwashing was a stable, valid and reusable method to recover the membrane flux in the micro-filtration. During backwashing, the reverse flow through the membrane removes the concentration polarization and cake or gel layers from the membrane surface. The effect of the backwashing conditions on the flux was studied. The obtained optimization conditions were as follows: backwashing pressure 0.6 MPa, backwashing time 5s and the backwashing interval 20min. The permeate flux could be raised about 50% compared with that without backwashing.

Abstract: A pilot-scale experimental system of filling gasoline into a tank was built to investigate gasoline vapor-air mass transfer in the tank gas space and the vapor evaporation loss from the tank in different operating conditions. The results showed that the higher the location of filling pipe exit inside the tank, the quicker the speed of the filling gasoline, and the higher the initial vapor concentration in the tank gas space, then the more severe the vapor-air convective transport and the larger the gasoline evaporation loss rates.

Abstract: Tri-n-octylamine-intercalated α-zirconium phosphate (TOA-ZrP) was prepared in the presence of (C₄H₉)₄NOH for the first time. The interlayer distance of (C₄H₉)₄NOH-intercalatedα-zirconium phosphate (B-ZrP) is 14.7 Å, larger than that ofα-ZrP (7.6 Å). The TOA-ZrP sample is highly crystallized with the interlayer distance of 22.3 Å. The molar ratio of TOA toα-ZrP in the intercalation composite was found to be 1/1.21. The composite can find application in solid extraction.

Abstract: The NaA/PTFE composite membranes were synthesized on polytetrafluoroethylene (PTFE) film by hydrothermal secondary growth (HSG) method and scratching (ST) method. The structure and morphology were characterized by XRD and SEM. The pervaporation(PV) performance of NaA/PTFE composite membranes were evaluated with dimethylformamide (DMF)/water mixtures. The XRD results showed that NaA/PTFE composite membranes kept the zeolite crystal feature of A type. The substrate, PTFE and zeolite were firmly combined together by the SEM photos. The results of PV showed that the flux and the separation factor of NaA/PTFE composite membrane prepared by HSG method with 4 crystallization times were 0.54 kg/m² h and 23, respectively. The flux of NaA/PTFE composite membrane prepared by ST method was much larger than that of NaA/PTFE composite membrane prepared by HSG method, but separation factor was lower.

Abstract: Three kinds of commercial PVA composite membranes with different crosslinking degrees (PVA-1, PVA-2 and PVA-3) were used to separate DMF/H₂O mixtures. Their pervaporation performance was investigated at different operation temperatures. The results showed that PVA-1 was the most suitable one for separating DMF/H₂O mixtures. When operation temperature was 60°C and downstream pressure was lower than 6kPa, flux reached to 0.59 kg·m^-2·h^-1 and separation factor was 33 for PVA-1 membranes. Aspen Plus^® was applied to simulate the normal distillation for retentate from pervaporation unit. Comparing with the two-effect distillation, the cost of concentrating DMF could be reduced 16.2% to 19.2% for DMF aqueous solution with different composition by hybrid processes. The cost would be the lowest for a hybrid process that concentrated the feed into 50wt% by pervaporation firstly, then concentrated retentate to 99.6wt% by two-effect distillation

Abstract: The porous SiO₂/TiO₂ bilayer antireflection coatings with self-cleaning capacity have been prepared by a sol-gel dip-coating method, the surfactant template, Pluronic F123 (PF123) was added to the sol as a pore generator. The performances of the coatings were analyzed with ultraviolet visible spectrophotometer (UV-Vis), scanning electron microscope (SEM) and atomic force microscopy (AFM). The self-cleaning function of coatings was evaluated by means of photocatalytic degradation of methyl orange in aqueous solution, and mechanical strength of the coatings has also been studied. The results indicate that the average transmittance of porous SiO₂/TiO₂ coating increases by 6% as compared to uncoated glass, the coating has a small particle size, a porous structure and a low roughness. After illuminated by ultraviolet light for 3 h, the 5 mg/L methyl orange can be degraded by 56.5%. In addition, the coating has an excellent mechanical strength.